The bioactive substance in Ganoderma lucidum, which is basically a fungus, is poly-saccharide, and is proven to be beneficial for antioxidant support, heptao-protective, immunomodulatory, and anti-hypertensive activities.
A study conducted on the bioactive polysaccharides of Ganoderma lucidum are active in promotion of functions of antigen presenting cells, humoral immunity, cellular immunity and mono-nuclear phagocytic system. All of these systems are related to immune system of human body. A research study conducted by You and Lin (2002) reveals that in vivo and in vitro injured macrophages by tert-butylhydroperoxide (tBOOH) showed significant improvement in their survival rate when they were treated intraperitoneally with G. lucidum poly-saccharide peptide (GLPP). Another study conducted by Zhu, Chen, & Lin (2007) revealed that low dose of G. lucidum poly-saccharides increased phagocytosis and cytotoxic activity of macrophages. It was studied that when T-lymphocytic culture (directly related to immune system) was treated with its poly-saccharide and it produced necrosis factor (alpha) and interferons ( Zhang & Lin, 1999). Other studies by Soniamol, Baby, Varughese, Kuttikkadan, & Kainoor (2011), Harris et al., (1984), Zhu et al., (2007) and Gao, Gao et al., (2005) showed that spores of Ganoderma lucidum not only increase T- lymphocytic cytotoxic activity but has great immunological effects by increasing T and B lymphocyte proliferation and production of antibodies. It was also believed to increase migratory activity of human primary neutrophils and in vitro inhibition of neutrophil apotopsis ( Hsu, Lee, & Lin, 2002).
On the basis of these research studies it can be concluded that polysaccharides of Ganoderma lucidum have their bioactive effect in-vitro and in-vivo on enhancement of immune system activities and those of macrophages i.e. T lymphocytes, B lymphocytes, and neutrophils. These research studies reveal that it has significantly beneficial effects on enhancement of immune activities of the human system which ultimately improves and helps make a stronger a defensive guard.